1. Field of the Invention
One aspect of the present invention relates to a communication device, and more particularly, to a process for performing short range communication by reducing electric energy consumption.
2. Description of the Related Art
There are mobile communication devices performing short range communication in addition to communication through a mobile communication network. A communication device of a counterpart of short range communication, for example, a mobile communication device, transmits/receives an image file and/or an address book by short range communication, etc.
Since a mobile communication device is operated by power stored in a battery, reduction of electric energy consumed in relation to the short range communication is required. Thus, the short range communication is performed in two types of communication systems.
That is, first, in communication by a first short range communication system whose power consumption is low, an identifier, etc., required for communication by a second short range communication system of a communication counterpart device are mutually transmitted/received. Using the identifier, high-rate communication by the second short range communication system is performed.
One example of the first short range communication system is a Near Field Communication (hereinafter, referred to as NFC) system standardized by International Organization for Standardization/International Electrotechnical Commission Joint Technical Committee 1 (ISO/IEC JTC 1). One example of the second short range communication system is a Bluetooth system and a wireless LAN system.
A communication rate by the NFC system is not surely high, but when it waits for a radio wave to be transmitted from a counterpart, electric energy is not consumed. Therefore the electric energy to be consumed can be reduced (for example, see JP-A-2004-364145 (Pages 2-3 and FIGS. 13, 14, and 15)).
However, a method disclosed in JP-A-2004-364145 does not consider reduction of electric energy to be consumed until the second short range communication system (high-rate communication system) ends.